init

README.md

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+# gh-proxy
+## 简介
+
+利用Cloudflare Workers对github release、archive以及项目文件进行加速，部署无需服务器且自带cdn。
+
+## 使用
+
+直接在copy出来的url前加`https://shrill-pond-3e81.hunsh.workers.dev/`即可
+
+也可以直接访问，在input输入
+
+注意，如果是项目文件会302到jsdeliver，由国内加速会更快。
+
+***大量使用请自行部署，以上域名仅为演示使用。***
+
+以下都是合法输入：
+
+ - 分支源码：https://github.com/hunshcn/project/archive/master.zip
+   
+ - release源码：https://github.com/hunshcn/project/archive/v0.1.0.tar.gz
+   
+ - release文件：https://github.com/hunshcn/project/releases/download/v0.1.0/example.zip
+   
+ - 分支文件：https://github.com/hunshcn/project/blob/master/filename
+
+ - commit文件：https://github.com/hunshcn/project/blob/1111111111111111111111111111/filename
+
+## 部署
+
+首页：https://workers.cloudflare.com
+
+注册，登陆，`Start building`，取一个子域名，`Create a Worker`。
+
+复制 [index.js](https://cdn.jsdeliver.net/hunshcn/gh-proxy@master/index.js) 到左侧代码框，`Save and deploy`。如果正常，右侧应显示首页。
+
+## 计费
+
+到 `overview` 页面可参看使用情况。免费版每天有 10 万次免费请求，并且有每分钟1000次请求的限制。
+
+如果不够用，可升级到 $5 的高级版本，每月可用 1000 万次请求（超出部分 $0.5/百万次请求）。
+
+## 链接
+
+[我的博客](https://hunsh.net)
+
+## 参考
+
+[jsproxy](https://github.com/EtherDream/jsproxy/)

index.js

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+'use strict'
+
+/**
+ * static files (404.html, sw.js, conf.js)
+ */
+const ASSET_URL = 'https://hunshcn.github.io/gh-proxy'
+
+/** @type {RequestInit} */
+const PREFLIGHT_INIT = {
+    status: 204,
+    headers: new Headers({
+        'access-control-allow-origin': '*',
+        'access-control-allow-methods': 'GET,POST,PUT,PATCH,TRACE,DELETE,HEAD,OPTIONS',
+        'access-control-max-age': '1728000',
+    }),
+}
+
+/**
+ * @param {any} body
+ * @param {number} status
+ * @param {Object<string, string>} headers
+ */
+function makeRes(body, status = 200, headers = {}) {
+    headers['access-control-allow-origin'] = '*'
+    return new Response(body, {status, headers})
+}
+
+
+/**
+ * @param {string} urlStr
+ */
+function newUrl(urlStr) {
+    try {
+        return new URL(urlStr)
+    } catch (err) {
+        return null
+    }
+}
+
+
+addEventListener('fetch', e => {
+    const ret = fetchHandler(e)
+        .catch(err => makeRes('cfworker error:\n' + err.stack, 502))
+    e.respondWith(ret)
+})
+
+
+/**
+ * @param {FetchEvent} e
+ */
+async function fetchHandler(e) {
+    const req = e.request
+    const urlStr = req.url
+    const urlObj = new URL(urlStr)
+    let path = urlObj.searchParams.get('q')
+    if(path)
+    {
+        return Response.redirect('https://' + urlObj.host + '/' + path, 301)
+    }
+    // cfworker 会把路径中的 `//` 合并成 `/`
+    path = urlObj.href.substr(urlObj.origin.length + 1).replace(/^https?:\/+/, 'https://')
+    const exp = /^(?:https?:\/\/)?github\.com\/.+?\/.+?\/(?:releases|archive)\/.*$/
+    const exp2 = /^(?:https?:\/\/)?github\.com\/.+?\/.+?\/(?:blob)\/.*$/
+    if (path.search(exp)===0) {
+        return httpHandler(req, path)
+    }else if(path.search(exp2)===0){
+        const newUrl = path.replace('/blob/', '@').replace(/^(?:https?:\/\/)?github\.com/, 'https://cdn.jsdelivr.net/gh')
+        return Response.redirect(newUrl, 302)
+    } else {
+        return fetch(ASSET_URL + path)
+    }
+}
+
+
+/**
+ * @param {Request} req
+ * @param {string} pathname
+ */
+function httpHandler(req, pathname) {
+    const reqHdrRaw = req.headers
+
+    // preflight
+    if (req.method === 'OPTIONS' &&
+        reqHdrRaw.has('access-control-request-headers')
+    ) {
+        return new Response(null, PREFLIGHT_INIT)
+    }
+
+    let rawLen = ''
+
+    const reqHdrNew = new Headers(reqHdrRaw)
+
+    const refer = reqHdrNew.get('referer')
+
+    let urlStr = pathname
+    if (urlStr.startsWith('github')) {
+        urlStr = 'https://' + urlStr
+    }
+    const urlObj = newUrl(urlStr)
+
+    /** @type {RequestInit} */
+    const reqInit = {
+        method: req.method,
+        headers: reqHdrNew,
+        redirect: 'follow',
+    }
+    return proxy(urlObj, reqInit, rawLen, 0)
+}
+
+
+/**
+ *
+ * @param {URL} urlObj
+ * @param {RequestInit} reqInit
+ */
+async function proxy(urlObj, reqInit, rawLen) {
+    const res = await fetch(urlObj.href, reqInit)
+    const resHdrOld = res.headers
+    const resHdrNew = new Headers(resHdrOld)
+
+    // verify
+    if (rawLen) {
+        const newLen = resHdrOld.get('content-length') || ''
+        const badLen = (rawLen !== newLen)
+
+        if (badLen) {
+            return makeRes(res.body, 400, {
+                '--error': `bad len: ${newLen}, except: ${rawLen}`,
+                'access-control-expose-headers': '--error',
+            })
+        }
+    }
+    const status = res.status
+    resHdrNew.set('access-control-expose-headers', '*')
+    resHdrNew.set('access-control-allow-origin', '*')
+
+    resHdrNew.delete('content-security-policy')
+    resHdrNew.delete('content-security-policy-report-only')
+    resHdrNew.delete('clear-site-data')
+
+    return new Response(res.body, {
+        status,
+        headers: resHdrNew,
+    })
+}
+